Answer:
x = 70
Step-by-step explanation:
Since the lines are perpendicular then ∠ AED = 90°, thus
x + 20 = 90 ( subtract 20 from both sides )
x = 70
The angle between two vectors is:
CosФ = u - v / Magnitude(u) x magnitude(v)
Magnitude of u = SQRT(7^2 + -2^2) = SQRT(49 +4) = SQRT(53)
Magnitude of v = SQRT(-1^2 +2^2) = SQRT(1 +4) = SQRT(5)
u x v = (7 x -1) + (-2 x 2) = -7 + -4 = -11
cosФ = -11 / sqrt(53) x sqrt(5)
cosФ = -11sqrt265) / 265
Ф =cos^-1(-11sqrt265) / 265)
Ф=132.51 degrees.
Answer as a compound inequality: 
Answer in interval notation: [-4, 2)
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Explanation:
The range is the set of all possible y outputs of a function. When dealing with a graph like this, we just look at the highest and lowest points to determine which y values are possible.
The lowest point occurs when y = -4. We include this value. So far we have
which is the same as 
The upper ceiling for the y value is y = 2. We can't actually reach this value because of the open hole at (-3,2). So we say that 
Combine
and
to get the compound inequality 
This says y is between -4 and 2, including -4 but excluding 2.
To convert this to interval notation, we write [-4, 2) where the square bracket says to include the endpoint and the curved parenthesis says to exclude the endpoint.